The preparation of dental restorations often includes milling or grinding the restoration from a dental blank that has a standardized size and shape. Such blanks are typically available in different tooth colors and may be selected in accordance with a particular tooth color of a patient's teeth.
Typically a dentist prepares a tooth to be restored in a patient's mouth, sends a dental impression from the patient's dentition along with tooth color information to a dental lab and obtains the finished dental restoration from the dental lab. The dental lab typically holds a stock of dental blanks from which an appropriate blank is selected for making the dental restoration. The size of the stock and the selection is always a compromise. On the one hand the stock size is desirably small but large enough to have an appropriate blank for many different dental restorations available. On the other hand the selection should be such that tolerances, in particular regarding the color, between the blank and the tooth color information obtained from the dentist are accepted but kept within limits. The making of dental restorations having rare colors or color compositions thus is particularly difficult to address and may require either a relatively large stock or the acceptance of large tolerances.
There are further approaches for providing individualized dental blanks WO 2013/122662 for example discloses a dental milling block comprising a dental article having an outer surface, the dental article having been produced based on personalized data, wherein the outer surface of the dental article is at least partially covered with a surrounding material.
The invention further relates to a process of producing a dental milling block, the process comprising the steps of: a) providing a personalized Data Set C containing geometry data of the dental article and color data related to said geometry data, b) generating a layer of hardenable material on a surface, c) applying a color agent to the layer of hardenable material of step b), wherein the color agent is applied to at least some regions of those areas of the layer of hardenable material which are related to the geometry data of the dental article, d) consolidating the result obtained in step c) thereby obtaining an at least partially hardened layer of material.
Although the current approaches for manufacturing of dental restorations may provide a variety of advantages, there is still a desire for a method of manufacturing dental restorations in a cost efficient manner and at a good aesthetic quality.